Where Are The New iPhones? Check Fremont, Calif. (AAPL)

Conventional wisdom is that Steve Jobs will unveil new iPhones at his WWDC event next week, and put them on sale shortly after. Which means that there have be pallets of new iPhones stacked somewhere in the U.S. right now. So where are they?

It seems that whatever Quanta is moving lately is keeping their facility packed. Outside, the roughly 168,000-square-foot facility boxes were piled in one parking lot in the early summer sunshine. Distinctive white boxes labeled "iMac" and bearing the Apple logo were stacked 10 deep alongside 20 pallets of identical unmarked brown boxes roughly stacked 10 deep and four abreast.

The real action, however, took place behind the building--and could only be seen from the parking lot of an adjacent company on the other side of a shallow creek. Workers hustled to maneuver pallets of the brown boxes around trucks from FedEx and Advanced Logistics. The area was crowded with more than a dozen empty trailers from "Xtra Lease" and others.

All around the trucks, workers wheeled around pallets of the plain brown boxes, some using forklifts, others with hydraulic dollies. A security guard working for the company across the creek from Quanta's facility approached this reporter before a thorough survey could be made.

Inside Quanta's building, workers weren't answering many questions. If you ask to see the new iPhone an employee calls the shipping supervisor. "Chris is really, really busy right now--he can't talk to you," the receptionist answered.

The plain brown boxes could contain almost anything, of course: Apple's mysterious new tablet computers, new Apple notebooks, even a product for one of Quanta's other customers. Or the boxes could be bursting with dozens of the stylish cartons Apple wraps around its iPhones.

Pictures taken of the boxes from a public sidewalk with a digital camera weren't good enough to pick up shipping labels or any other telling details.

While Chris was busy we did manage to catch one employee at the end of his smoke break. "Are you with a magazine or something?" he asked as he noticed a reporter, notebook in hand, coming his way.

Are the new iPhones inside? "No, no," he said, before flashing a grin and heading back into the building. "If so, I'm not at liberty to discuss it."